scholarly journals A method for studying the metabolic activity of individual tardigrades by measuring oxygen uptake using micro-respirometry

2020 ◽  
pp. jeb.233072
Author(s):  
Bjarke H. Pedersen ◽  
Hans Malte ◽  
Hans Ramløv ◽  
Kai Finster
Keyword(s):  
Steady State ◽  
Reproductive Success ◽  
Environmental Factors ◽  
Oxygen Uptake ◽  
Respiration Rate ◽  
Metabolic Activity ◽  
Life Stages ◽  
Respiration Rates ◽  
Single Organism ◽  
Insight Into

Studies of tardigrade biology have been severely limited by the sparsity of appropriate quantitative techniques, informative on a single-organism level. Therefore, many studies rely on motility-based survival scoring and quantifying reproductive success. Measurements of O2 respiration rates, as an integrating expression of the metabolic activity of single tardigrades, would provide a more comprehensive insight into how an individual tardigrade is responding to specific environmental factors or changes in life stages. Here we present and validate a new method for determining the O2 respiration rate (nmol O2 mg−1 hour−1) of single tardigrades under steady state, using O2-microsensors. As an example, we show that the O2 respiration rate determined in MilliQ water for individuals of Richtersius coronifer and of Macrobiotus macrocalix at 22 °C was 10.8±1.8 nmol O2 mg−1 hour−1 and 13.1±2.3 nmol O2 mg−1 hour−1, respectively.

Validation of On-line Respiration Meter and its Applications by Computer Simulation

1992 ◽  
Vol 26 (5-6) ◽  
pp. 1355-1363 ◽  
Author(s):  
C-W. Kim ◽  
H. Spanjers ◽  
A. Klapwijk
Keyword(s):  
Steady State ◽  
Activated Sludge ◽  
Respiration Rate ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Mass Balances ◽  
Short Term ◽  
Respiration Rates ◽  
On Line ◽  
Made In

An on-line respiration meter is presented to monitor three types of respiration rates of activated sludge and to calculate effluent and influent short term biochemical oxygen demand (BODst) in the continuous activated sludge process. This work is to verify if the calculated BODst is reliable and the assumptions made in the course of developing the proposed procedure were acceptable. A mathematical model and a dynamic simulation program are written for an activated sludge model plant along with the respiration meter based on mass balances of BODst and DO. The simulation results show that the three types of respiration rate reach steady state within 15 minutes under reasonable operating conditions. As long as the respiration rate reaches steady state the proposed procedure calculates the respiration rate that is equal to the simulated. Under constant and dynamic BODst loading, the proposed procedure is capable of calculating the effluent and influent BODst with reasonable accuracy.

scholarly journals Metabolic activity of fresh-cut 'Pérola' pineapple as affected by cut shape and temperature

2006 ◽  
Vol 18 (3) ◽  
pp. 413-417 ◽  
Author(s):  
Lucimara R. Antoniolli ◽  
Benedito C. Benedetti ◽  
José M.M. Sigrist ◽  
Men de Sá M. Souza Filho ◽  
Ricardo E. Alves
Keyword(s):  
Gas Chromatography ◽  
Respiration Rate ◽  
Metabolic Activity ◽  
Cold Storage ◽  
Continuous Flow ◽  
Respiratory Activity ◽  
Ethylene Synthesis ◽  
Respiration Rates ◽  
Cold Room ◽  
Fresh Cut

The effects of cut shape and temperature on the respiratory activity and ethylene synthesis of fresh-cut 'Pérola' pineapple were investigated. Two experiments were carried out. In the first, slices and chunks were placed in air-tight packages kept at 4 or 10ºC. Gas samples were taken every 2 h during 12 h and analysed by gas chromatography. In the second experiment, peeled fruits, slices and chunks were placed in air-tight glass jars connected to a flowboard installed in a cold room at 5 ± 1ºC. This system provided a continuous flow of humid and cold air during 14 d. Respiration rate was determined every 2 h, during the first 12 h, then daily for 10 d and on days 12 and 14. Ethylene synthesis was not detected during 12 h of evaluation. The lower respiration rates that occurred when fruits were stored at 4ºC indicate that this condition provides greater shelf life for the fresh-cut product. The initial respiration rate of slices and chunks stored at 5ºC doubled as compared with peeled fruits under the same conditions. The respiratory behaviour of slices and chunks was very similar during 14 d of cold storage, with respiration rates between 1.96 and 4.10 mg CO2 kg-1 h-1.

Influence of environmental factors on respiration of excised tissues of American oysters, Crassostrea virginica (Gmelin)

1971 ◽  
Vol 49 (3) ◽  
pp. 353-360 ◽  
Author(s):  
J. A. Percy ◽  
F. A. Aldrich ◽  
T. R. Marcus
Keyword(s):  
Environmental Factors ◽  
Crassostrea Virginica ◽  
Respiration Rate ◽  
Seasonal Changes ◽  
Adductor Muscle ◽  
American Oyster ◽  
Respiration Rates ◽  
Excised Tissues ◽  
Seawater Medium

Respiration rates of excised gill, mantle, and adductor muscle of the American oyster, Crassostrea virginica (Gmelin), were measured by the Warburg technique at a number of temperatures and salinities and at various times during the year. Dilution of the seawater medium stimulates gill respiration, has no significant effect on mantle respiration and inhibits adductor muscle respiration. Rate–temperature curves are presented for all three tissues. Respiration rates of gill and mantle declined by about 17% in the autumn, while adductor muscle respiration increased by about 14%. A number of possible explanations for the seasonal changes are discussed.

EFFECT OF VARIOUS HORMONES ON THE KIDNEY RESPIRATION RATES IN THE CUTTHROAT TROUT (SALMO CLARKI CLARKI)

1960 ◽  
Vol XXXIII (III) ◽  
pp. 428-436 ◽  
Author(s):  
W. N. Holmes
Keyword(s):  
Single Dose ◽  
Respiration Rate ◽  
Cutthroat Trout ◽  
Adaptive Mechanism ◽  
Respiration Rates ◽  
Salmo Clarki

ABSTRACT Relatively large doses of vasopressin administered intraperitoneally to the trout significantly enhanced the kidney respiration rate. In contrast to vasopressin a single dose of oxytocin depressed the kidney Qo2 value. This depression continued throughout the observed 24 hour period after injection. Cortisol enhanced the kidney Qo2 values significantly and to a greater extent than vasopressin. These results are discussed in relation to possible adaptive mechanism in euryhaline species of teleosts.

Decrease in soil microbial activity and biomasses owing to nitrogen amendments

1983 ◽  
Vol 29 (11) ◽  
pp. 1500-1506 ◽  
Author(s):  
B. Söderström ◽  
E. Bååth ◽  
B. Lundgren
Keyword(s):  
Respiration Rate ◽  
Laboratory Experiments ◽  
Coniferous Forest ◽  
Soil Microbial Activity ◽  
Urea Treatment ◽  
Soil Microbial ◽  
Respiration Rates ◽  
Nitrate Addition ◽  
Transitory Effect ◽  
Forest Podzols

Microbial biomass and soil respiration rate decreased after application of 150 kg NH4NO3–N∙ha−1 to different coniferous forest podzols. The decrease was already found 3 months after fertilization and was still evident after 3–5 years. Changes in pH, organic matter, or water content in the soils could not explain the decreases. In laboratory experiments, several unfertilized forest soils were treated with 2 mg of NH4NO3–N or of urea–nitrogen∙g wet soil−1. The ammonium nitrate addition resulted in severe depressions of the respiration rates during and up to 175 days of incubation and the decrease was evident after about 1 week. The urea treatment initially increased the respiration rate of the soils, but this appeared to be a transitory effect.

Stress level in wild harbour porpoises (Phocoena phocoena) during satellite tagging measured by respiration, heart rate and cortisol

2009 ◽  
Vol 89 (5) ◽  
pp. 885-892 ◽  
Author(s):  
I.G. Eskesen ◽  
J. Teilmann ◽  
B.M. Geertsen ◽  
G. Desportes ◽  
F. Riget ◽  
...  
Keyword(s):  
Heart Rate ◽  
Respiration Rate ◽  
Serum Cortisol ◽  
Phocoena Phocoena ◽  
Heart Rates ◽  
Stress Effects ◽  
Respiration Rates ◽  
Stressed Animal ◽  
Cortisol Levels ◽  
Satellite Tagging

During satellite tagging of harbour porpoises (Phocoena phocoena), heart rate, respiration rate and cortisol value were measured to evaluate stress effects during handling and tagging. Respiration rates were obtained using video recordings, heart rates were recorded and serum cortisol levels were analysed from blood samples. Differences in heart rates, respiration rates and cortisol levels before and during the tagging events were investigated. An overall significant decrease of 31.5% in respiration rate was found during the tagging event period, while mature porpoises respired significantly more often than immature individuals. Though significant differences in heart rates were found for some individuals, no general significant change for all animals was detected. We found no correlation between cortisol concentration and either heart rate or respiration rate, nor did we find any relationships between cortisol and month of year, sex and body length. As high individual variations occurred in response to tagging of harbour porpoises, it is not possible to give general advice based on the factors investigated, on how to reduce stress during handling. However, pouring water over the animal and lowering it into the water seem to stabilize a stressed animal. Therefore, general precaution and individual judgement based on experience is essential when handling wild harbour porpoises.

The effect of the acanthocephalan Pomphorhynchus laevis upon the respiration of its intermediate host, Gammarus pulex

Parasitology ◽  
1974 ◽  
Vol 68 (2) ◽  
pp. 271-284 ◽  
Author(s):  
A. E. Rumpus ◽  
C. R. Kennedy
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Host Population ◽  
Gammarus Pulex ◽  
Multiple Infections ◽  
Pomphorhynchus Laevis ◽  
Respiration Rates ◽  
Physiological Processes ◽  
Stage Of Development ◽  
Host Parasite

The respiration rates of individual Gammarus pulex infected by larval Pomphorhynchus laevis were investigated with particular reference to the stage of development of the host and parasite and to the water temperature. At 20°C the oxygen consumption of Gammarus of all sizes was reduced by an average of 19·3 % by the presence of cystacanths of the parasite, but was unaffected by the presence of acanthellae. It is considered that the small size of this larval stage, in relation to that of its host, is responsible for the failure to detect an effect. Multiple infections did not exert any greater effect upon host respiration than single cystacanths, nor did it appear that the parasite had different effects upon hosts of different sexes. At 10°C no significant differences were observed between the respiration rates of infected and uninfected gammarids. The parasite was probably still depressing the host respiration rate at this temperature, but the oxygen uptake of G. pulex is so low that the differences between infected and uninfected individuals were too small to be detected. The parasite has a direct effect upon the physiological processes of the host, but neither the mechanism of this nor the reasons for the different effects found in different host-parasite systems are yet understood. Despite the pronounced effect of P. laevis on respiration of individual hosts, its effect upon the oxygen consumption of a natural host population is small since only a small proportion of the population carries infections and water temperatures remain below 10°C for over half the year.

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